# How to UV Smart-Unwrap Properly?

I am lazy. I select my mesh, U -> Smart Unwrap -> Ok. And I would go on and texture it with SubstancePainter or Photoshop. I only create low Poly stuff and this has worked perfectly sofar. Everything is in correct angle and proportion:

More and more often I get resulst like these, even though I have "Correct Aspect" checked. This makes it impossible to work with:

Tweaking values doesn't fix anything. The Unwrapped Mesh is in inappropriate proportions and it stays this way. It's actually FASTER to redo the entire model and unwrap it again than to complicately mark seams and fiddle with the Mesh in the UV-Editor. Unless of course it comes out bugged again, but sofar that was never the case. The model is pretty much equal, the result is totally out of whack.

WHY???

What is happening here behind the curtains that I don't see/understand?

• Chances are your objects have a non uniform scale. Try to apply scale (Ctrl+A->Scale). – Dimali Aug 20 '17 at 13:39
• Does disabling "Stretch to UV bounds" make any difference? – Serge L Aug 20 '17 at 18:52
• Neither solutions work. – AzulShiva Aug 20 '17 at 20:59
• Related The python code to the smart unwrap. – batFINGER Jun 24 '18 at 15:06

I have found a Solution. This is not really an answer as to why it is happening but it's too long to put into a comment and at least it fixes the problem.

• Go into Edit Mode

• Press P (for Seperate) and select By Loose Parts

• Create a Cube somewhere in the scene

• Select all the loose parts of your model and then the cube so the
cube is the active object and press Ctrl+J (for join)

• Go back into Edit mode and delete the Cube, unwrap: done.

This is the same procedure by the way that I frequently use to set the rotation and scale of an object to 1.

• It probably works because in the joining process the meshes take on a uniform scale (the scale of the cube). Have you tried applying scale as @Dimali suggested? It would be easier. – Mentalist Aug 21 '17 at 11:37
• Yes. That did not work. – AzulShiva Aug 22 '17 at 9:42
• Interesting. I wonder if the unwrapping algorithm is using the cube mesh like a bounding box to set the scale, or something like that. Can you upload the .blend to Blend Exchange? – Mentalist Aug 22 '17 at 10:25
• I will if I encounter the error again. Unfortunately I have no blend file right now with this problem. – AzulShiva Aug 30 '17 at 20:57